Removable denture



June 26, 195] R, J, MAN|OLA 2,558,186

REMOVABLE DENTURE Filed April 26, 1947 INVENTOR. v ROE/ZT d MAN/OLA0560.

y JA M55 a. MAN/OLA, A www.

Patented June 26, 1951 UNITED STATES PATENT OFFICE REMOVABLE DENTUREApplication April 26, 1947, Serial No. 744,205

9 Claims.

This invention relates to improvements in removable dentures.

One object of the invention is to provide improved dentures whichutilize the natural undercuts of the abutment teeth for retaining thedenture in proper position Vbut having parts so formed that the denturescan readily be placed in position or removed for cleansing.

Another object of the invention is to provide a denture which is adaptedto seat in van edentulous area defined by natural undercut mesial anddistal surfaces of the abutment teeth and which avoids the formation ofobjectionable food traps or cavities by closing all the interproximalspaces spanned by the denture.

An additional object of the invention is to provide a denture of twocooperating parts which are separately insertable into the edentulousarea or space for which they were made and to be releasably latchedtogether while in said space and which, while in said space, closelycontact the mesial and distal surfaces of the abutment teeth forretention in position against vertical and lateral displacement.

Other objects of the invention relate to various features ofconstruction which willbe apparent from a consideration of the followingspecification and accompanying drawings, wherein Figure 1 is a brokenlower plan view of a set of upper teeth showing an improved denture inposition;

Fig. 2 is an elevation of the teeth of Fig. l as viewed from a positionindicated by line 2-2 of Fig. 1 and showing an artificial denture inplace;

Fig. 3 is a view similar to Fig. 2 but illustrating the denture inposition in dotted lines and in a removed position in full lines;

Fig. 4 is a broken enlarged buccal view of the denture in longitudinalsection and showing the relation thereof to the two abutment teeth;

Fig. 5 is a sectional view taken on line 5 5 of Fig. 4;

Fig. 6 is a perspective view of the two sections of which the improveddenture is formed, the sections as shown being separated and inverted;

Fig. 7 is a view similar to Fig. 4 but illustrating a modifiedrelationship between one denture section and the contiguous abutmenttooth.

In the drawings, a set of natural upper teeth are shown, two of whichhave been replaced by a removable denture that is illustrative of thepresent invention. The two natural teeth that have been removed are thesecond right bi-cuspid and the first molar. Hence, the abutment teethfor the edentulous area caused by the removal of the two natural teethare the first right bi-cuspid Ill and the second right molar Il. Asindicated in Fig. 2, the distal surface of tooth I0 and the mesialsurface tooth II are undercut surfaces, that is, each convergesgenerally toward the root tip of the respective tooth. These undercutsurjfaces mentioned result from the fact that the abutment teeth, asillustrated, are broader" at the outer portions `than at the gum-line.These undercut surfaces have been a source of trouble 4in makingconventional removable partial dentures that avoid the formation of foodtraps, but such undercut surfaces are utilized in the presentimprovements for retention of the dentures in place and without the useof bars and clips of the types that heretofore commonly have been used.

The denture illustrated in Figs. l to 6 comprises two coacting separablesections A and B which are insertable in the edentulous area in theorder named and are removable in the reverse order. Fig. 6 illustratesthe sections A and B as viewed from the right in Fig. l, that is thelingual side, and also shows the sections in inverted relation, Fig. 1being a View of the upper teeth. The section A is a casting of metal ora moulding of appropriate plastic and comprises a surface I2saddle-shaped in accordance with the gum surface or ridgeportion overwhich it is to be worn, as indicated in Fig. 5. The body I3 of sectionAhas formed thereon a latching member I4, preferably on the lingual sideof the section, which cooperates with a mating latch member of section Bfor releasably retaining the members in co-operative relation as will belater described. Extending upwardly from the body I3 is a verticalportion' or pillar I5 provided with a wall or surface I6 that is moldedor cast to conform to the mesial surface I1 of the abutment tooth Il.Hence, the wall I6 is not only curved in horizontal cross-sectiongenerally to conform to the shape of the mesial surface of the tooth IIwith which the surface It contacts, but it is inclined from the verticalreciprocally with respect to the undercut mesial surface ofr the toothII. In Fig. 4 the relation of the surface I6 of the section A to themesial undercut surface II of tooth II is clearly indicated.

Thevpillar I5 is provided with a rearwardly,

that is, distally, directed lug I8 adapted to seat in a recess that maybe ground, if necessary, in the occlusal surface of the tooth II asindicated at I9 in Fig. 4. The ,forward or mesial surface 2i) of thepillar I5 is disposed in a plane that is parallel to the medial line ofthe undercut distal surface 2| of the abutment tooth I0 as indicated inFig. 4. Hence when the section A of the improved denture has been placedin position in the edentulous space, the two surfaces 2t and 2l beingparallel will accommodate insertion of the section B in a directionparallel with the medial lines of the surfaces 26 and ZI as will be morefully described hereinafter.

Again referring to Fig. 6, it will be seen that the section B carriesthe artificial teeth 22 and 23 which replace the natural teeth abovementioned. As stated, the plate of section B, as shown in Fig. 5, hasits gum contacting surface 24 shaped 1in conformity with the contour-of.theportionof `the gum ridge over which it isto seat. The -rnesialsurface 25 of the section B isinclined'complementarily with respect tothe undercut distal surface 2| of the tooth I 0 and transverselycorresponds to the transverse curvature or contour of the tooth whilethe distal `end of section B has a .surface `section 26 vthat isinclined for .Contact :with vthe surface .2D of section A. The mesial.end portion of .the section B, as shown, also .is

provided with a lug `2T, that extends mesially nontoa seat. 28, Vground.if necessary, in. an occlusal surface of the .abutment tooth VIIl asindicated .in Fig. 4.

The artificial teeth .22 and 23 are secured to thesection B -byanyapproved means, such as .by lpins or studs .2S .formed integrally with.the

.section in the casting or .moulding thereof and `which .enter recesses3B provided .in the teeth. Cement retains .the teeth in proper relation.

The ysurface24 ofthe sectionB -is shaped, as

stated, to conform to the respective gum surface except that at thedistal .end of suchsur- .face .it is relieved, as at 3l, as indicated inFigs. 4.and 5, foriittingover the upper portion of the body.I3of,section A .whereby Vthe two upper surfaces of sections A v.and Bprovide substantially -.a continuous 4ridge-contacting andridge-conforming surface .when the sections are inoperative position.The lower `lingual portion of section B, distally considered, isprovided with a latch portion 32 Vcomprising Va groove or .channel 33whereby when the sections have been moved into .flnalseating position inthe edentulous area, `will engage the latch .portion .I4 of section Afor ,latchingthe sections together. As will benoted in Fig..5,therelieved portion of thegum contacting .surface of the section B is,defined by a wall v311 that preferably vis inclined or undercut-slightly -for .rmlyengaging-.the complementary or .mating .wall .35 of.the sectionA whereby the Alatch portion 432, which is made sufficientlythin to render it -adequately resilient, may be sprung slightly .underYthe camming .action of the rib-'like `'latch portion I4, to cause `thegroove 3,3 to snap over the -rib i4 and so releasably retain the denture.sections .in position.

As Will .be apparent from the foregoing, the -sections .A and B aremoulded or cast ,to fit the `edentulous area of a particular patient andhence ,all sections V.A and B of the improvements will not be of theprecise shape shown the .draw- .ings .nor-will the angles and crosssectional shapes of the distal and mesial sur-faces .of the .denture beprecisely as illustrated. The distal and mesial surfaces of .theabutment teeth however, or at .least one of `such surfaces, must .be of.an underl:cut form for `taking full advantage ofthe presentimprovements.

In placing .the sections A and B into Voperative `position, vthe sectionA is first `placed. -in .the edentulous space with the lug .I8 upon theseat I 9 and with the wall I6 contacting the mesial `311 and 35 of thesections are inter-engaged where..

upon slight pressure upon the resilient latch sec- :tion T32 of sectionB causes the latch members (in the particular form shown comprising therib M .and thecooperating groove 33), to snap relatively intoengagement. In pressing the section B into position, the wedging actionof the inclined surface '2B of section A on the reciprocally .inclinedsurface 26 of section B tends to urge the sections longitudinally inopposite directions and thereby effect close inter-engagement of thesurfaces f6 'and I1 and 2I and 25, respectively.

Thelugs ISand 21 .receive the gum-wise vthrust of lthe teeth 22 and 23inbiting or chewing and thus relieve the gum ridgesfrom excessivepressure. The lugs .also restrain rocking movement of the denture withrespect to the .ridge of the gums as an axis, and cooperate with thearcuate,

gum fitting lower surfaces I2 and 24 of .the sections A and B, .as well.as with the .arcuate shape of the mesial and distal surfaces .ofthedenture (which closely contact .the respective surfaces of .the abutmentteeth) in inhibiting lateral displacement of the denture, that islingually or'buccally. The movement ofthe denture in a verticaldirection, that is,.avvay from the gum surface `on which the denturefits, is restrained vby the coaction .of the end walls i6 and .25 of the.sections A and B with Vthe respective contacting .undercut walls oftheabutment teeth. Hence `when the denture sections have been placed inposition in the .edentulous .area .and latched together, they are.retained against .vertical displacement by the Wedging or key-stoneactiondescribed. The denture can be removed readily irst'by lifting up-on the latch portion 32 of section B and thereupon removing section Band then section A.

Fig. 7 lillustrates Ythe adaptation .of the structure shown in Figs. lto .6 `inclusive to an edentulous area having .but one undercut.toothsurface, indicated at I1. The opposite end of .the

areaisdeiined cyan abutment tooth 1.0 having a vertical surface 136. The.denture shown in Fig. '7 is in vall respects similar to .the .denture-above ldescribed .except as modified for .coaction with the toothindicated as ID which has a vertical rather than an undercut surface.The cooperating surface ,31 .of the .denture section B .condorms/to thesurfacer. Assuming that the denture sections .are latched together asdescribed'in `connection. with .the form shown inFigs. '1 .to'6,

the denture of Fig. 7 will not move vertically .by .gravity (assumingitis an `upper denture) since .any vertical movement would cause theundercut surface AI 'l' of .tooth I i to effect a wedging action on Vthecomplementary surface I6' ofthe section A', .the component of whichwould tend to Aforce the denture to the right as viewed in Fig. 7. Suchmovement, however, is resisted by the abutment tooth .IBL Likewise `the4right hand end of the dentureshovvn in Figj? Vcannot swing downward--ly .about v.the'lug 'I8' of section A' as a pivot for the .reason thatno clearance 'for such arcuate .movement is present Within theedentulous area.

It Ywill be obvious -that vthe dentures embodying the invention shownand described are adapted for use as lower dentures as well as upperdentures and that the relative arrangement of sections A and B may bereversed. Also it will be seen that a section, such as section B, may beprovided with more than two teeth where the edentulous area requires agreater number of teeth than those shown, or with a single tooth. Itwill also be apparent that the improved denture, comprising the twosections A and B arranged in end to end relation, is retained as a unitagainst vertical displacement by reason of the keying action between therespective contiguous surfaces of the abutment teeth and the remote endsl5 and 25 of the sections which are reciprocally or complementarilyshaped to conform to or mate with the respective surfaces of the teeth.It will also be apparent that slight movement of the sections A and B inaxial directions may occur as section B is pressed into firm position inthe edentulous spaces due to the coaction of the reciprocally shapedinclined surfaces 29 and 26 which tends to move the sections in oppositedirections against the respective teeth IIJ and I l. The close fittingrelationship of the remote end portions of the denture and the abutmentteeth avoids the formation of food traps 01 cavities between theabutment teeth and the adjacent artificial teeth since the respectiveinterproximal spaces are closed by the adjacent portions of the denturesections A and B. Likewise, since the inclined surfaces 20 and 26 arereciprocally formed, they closely intert and exclude food particles frombetween the sam-e and since they are retained in such interttingrelation by the latching means they, in turn, retain the remote ends ofthe sections in close contact with the abutment teeth.

While removable dentures have been Shown and described that areillustrative of the invention, various changes in the details shown maybe tions adapted to be positioned consecutively in said space and eachprovided With a remote end wall reciprocally shaped with respect to andadapted to contact one of the undercut surfaces of the respective teeth,said sections being provided with reciprocally shaped interttingadjacent surfaces a portion of each of which surfaces is disposed at anangle at least as great as the angle of the undercut wall of the secondabutment tooth and adapted to urge the sections in opposite directionsas the second of said sections is pressed into intertting relation withthe rst section within said space for thereby urging said remote endWalls into contact with the said surfaces of the respective teeth forrestraining Vertical movement of the denture from said space, and meansreleasably securing said adjacent ends of the sections in saidinterfitting relation.

2. A removable denture for use in an edentulous space dened by undercutwalls of two abutment teeth comprising a pair of denture sectionsadapted to be positioned consecutively in said space and each providedwith a remote end wall reciprocally shaped with respect to and adaptedto contact one of the undercut surfaces of the respective teeth, saidsections being provided with reciprocally shaped intertting adjacentsurfaces a portion of each of which surfaces is disposed at an angle atleast as great as the angle of the undercut wall of the second abutmenttooth 'and adapted to urge the Vsections in opposite directions as thesecond of said sections ispressed into intertting relation with the rstsection within said space for thereby urging said remote end walls intocontact with the said surfaces of the respective teeth for restrainingvertical movement of the denture from said space, and cooperating snapaction latch portions on said sections for releasably retaining theadjacent ends of said sections in said intertting relation.

3. A removable denture for use in an edentulous space dened by undercutWalls of two abutment lteeth comprising a pair of denture sectionsadapted to be positioned consecutively in said space in end-to-endrelation, the remote ends of said sections being shaped reciprocallywith respect to the respective undercut walls, the other ends of saidsections having reciprocally shaped surfaces disposed in reciprocallyinclined planes for intertting contact upon the position,

ing of said sections in said space with said lremote ends in contactwith said walls, and releasable means for securing said adjacentsurfaces of the sections in intertting contact and retaining said remoteends in contact with said Walls whereby said remote ends restrainvertical displacement of the denture from said space.

4. A removable denture for use in an edentulous space dened by undercutwalls of two abutment teeth comprising a pair of denture sectionsadapted to be inserted consecutively in said space, the rst insertablesection having a tooth contacting end wall reciprocally shaped forcontact with the' undercut wall of one of said teeth and having anopposite end portion providing a surface disposed at an angle parallelto the angle of the undercut portion of the other abutment tooth, saidsecond insertable section having an end wall shaped reciprocally withrespect to the undercut wall of the latter tooth forcontactng the sameand having an opposite end wall portion providing a surface shaped forinterfitting contact withsaid surface of the first section and disposedin a plane parallel to the plane of said surface of the 'first sectionand adapted to contact the same when the sections are in positionyinYsaid space, and means for releasably retaining said surfaces of thesections in contact for 're'- taining the said tooth-contacting ends ofthe respective sections in engagement with the undercut walls of therespective abutment teeth.

5. A removable denture'for use in an edentulous space defined byundercut Walls of two abutment teeth comprising a pair of separablesections insertable consecutively in end-to-end relation in said space,the first insertable section having an end wall reciprocally shaped forcontact with the undercut wall of one of said teeth, the secondinsertable section having an end Wall shaped reciprocally for contactwith the undercut wall of the second tooth, the other end portions ofthe sections having cooperating inclined surfaces reciprocally shapedfor intertting contact when the sections are in position in said spaceand being arranged in planes enabling said second section to be insertedin said space in a direction paralleling the plane of the undercut wallof said second tooth.

6. A removable denture for use in an edentulous space defined byundercut walls of two abutment teeth comprising a pair of separablesections insertable consecutively in end-to-end relation in said space,the first insertable section having an end wall reciprocally shaped forcontact with the undercut wall of one of said teeth.

assen se V,the*second.inseriamo section having an .end wall shapedreciprocally forrcontact with the under- -:cut wall-of the `secondtooth, the .other endpor- 'ftionsfof the sections providing cooperatingsuracesreciprocally shaped for intertting contact .when -the 4sectionsare in position in -said space and being arranged in inclined planesenabling ,said-second section to be inserted in the spacein za directionparalleling the plane of the underout Wall'of -said second ltooth, Aandmeans for re- .leasably latchingsaid .sections together in said -end-pto -end relation.

7. iA removable denture for use in .an `eden- :tulous Aspace ,'denedk,by `undercut walls of two abutment teeth comprising .a pair ofseparable :Sections insertable consecutively in end-to-end 'relation insaid space, the first insertablesection I.having 'an-end wallreciprocally shaped for contactwith'the undercut-wall of one of vsaidteeth, `the second insertable section vhaving an end wall shaped-reciprocally for contact with the under- :eut wall ofthe second tooth,the other ends of the :sections-:having cooperating surfacesreciprocally -shapedfor intertting contact when the sections areyin:position in said space and arranged in planes inclined at `Yan angle at-leastfas great as the angle yof the undercut wall of said secondabutment tooth for enabling said second section `toibefinserted inthespace in a direction paralleling the vplane-of 'the undercut wall ofsaid second tooth, and Y,cooperative,latchng elements on the VAlingualsides-.of said sections for reieasably latchin g the sections inv.end-to-end relation in said lspace.

8. -A removable `denture for use in an edentulous space defined `byundercut Vwalls of two A:abutment iteethcomprising a pair of separable,sections insertable consecutively in v,end-to-end relation in saidspace, the iirst insertable sec- `:tion :having an :end wallreciprocally shaped for -contaot qwith lthe undercut .wall of Aone ofsaid `teeth, the second inserta-ble Ysection having an endfwall shapedreciprocally for Contact with the .undercut wall Lof the secondtooth,the other ends `:of athe sections having cooperating .inclinedsurfacesreciprocall-y shapedfor intertting contact =whenzthe ksections`rare in position insaid space and Abeing arranged in Aplanesenablingsaid sec- `ond sectionto beinsertedin the space in a .direc-.tionparalleling the tplane of the undercut vwallvof 8 said second-tooth, and a pair of releasable latching elements on thelingual side'of said sections .comprising va rib on one section and `a :iiexible,portion of the other section provided Ywith va `receiving recessarranged for snap-engagement with .said rib.

9. kA removable denture for use vin an eden- ,tulous/space between two.abutment teeth one lof ywhich has an undercut abutment Wall and the`,other of .which has a vertical abutmentwail, said denture comprising apair of Ysections Aadapted to be ,inserted consecutively in end tolendrelation in said spaceand of acombined lengthtofll said ,parallelsurfaces reciprocally shaped for intertting Contact when lthesectionsare lin position in said space and'being arranged at ari-angleoonvergent with respect 'to the abutment wall of said Vsecond tooth inthe direction of the root of `the tooth for enabling the second sectionlto -be inserted inposition in'a direction -paralleling 4the ,plane ofthe abutment wall'o said second tooth and cooperating to :exertendwisethrusts on the vsections as Athe second section is Vinserted inposition'thereby pressing the end Walls of -the sections into contactwith the respective abutment walls .of `the teeth, 'and means forYreleasably Alatchingtthe contacting parallel surfaces of the sectiontogether.

JAMES J. MANIOLA, Administrator ofitheEstate of Robert J. M am'ola,

Deceased.

REFERENCES CITED The following references are of record inthe .file of.this pa-tent:

UNITED ,S'IATES PATENTS 'Number Y Name Date 1,590,363 y Gisske June 29,1926 1,641,887 v("oldfarb Sept. 6, 1927 1,976,085 Neurohr Oct. 9, `19342,469g339 Man-iola vvMay 3, '1949

